https://github.com/iterami/UnitConverter.htm/blob/gh-pages/js/main.js https://github.com/ben-ng/convert-units https://github.com/dubbs/measure https://www.npmjs.com/package/unitconvert https://www.npmjs.com/package/convert-units https://www.npmjs.com/package/node-units http://mathjs.org/docs/datatypes/units.html https://github.com/gentooboontoo/js-quantities http://stackoverflow.com/questions/865590/unit-of-measure-conversion-library